I had just looked at the Cut Sheet and it says:
1” (2.54cm) Titanium diaphragm compression driver mated to 90° x 60° square Tractrix® Horn
So the horn is designed to offer 90 degree horizontal dispersion and 60 degrees of vertical dispersion when the speaker is in the horizontal position.
If you turn the speaker vertical, you then get the opposite....60 degrees of horizontal dispersion and 90 degrees of vertical dispersion.
Now how much will 30 degrees of dispersion make a difference, I have no idea. Just something to consider.
I have 3 RC-7's, so I'll take a look at those specs and go from there.
thanks very much